A simplified model of an industrially relevant fluid-particle flow system is analyzed using linear stability theory. Instabilities of the uniform state of a fluidized bed are investigated in response to small flow perturbations. Students are expected to perform each step of the computational analysis, and physical insight into key mechanistic…

Semiconductor quantum dots are at the forefront of materials science chemistry with applications in biological imaging and photovoltaic technologies. We have developed a simple laboratory experiment to measure the quantum-dot size from fluorescence spectra. A major roadblock of quantum-dot based exercises is the particle synthesis and handling;…

Background: Assessing actual consumption of school cafeteria meals presents challenges, given recall problems of children, the cost of direct observation, and the time constraints in the school cafeteria setting. This study assesses the use of digital photography as a technique to measure what elementary-aged students select and actually consume…

When people read temporarily ambiguous sentences, there is often an increased prevalence of regressive eye-movements launched from the word that resolves the ambiguity. Traditionally, such regressions have been interpreted at least in part as reflecting readers' efforts to re-read and reconfigure earlier material, as exemplified by the Selective…

Surprisingly little is known about the extent of children's knowledge about number beyond their ability to recite, read and write numbers and count quantities of objects. There is little information on the extent to which children are aware of how number is used in their everyday environment or of how much they gain from such early exposure. The…

This article presents three mathematics lessons in a social justice setting of learning about poverty. Student activities include budgeting, graphic data representation, and linear regression, all in the context of connecting, communicating, and reasoning about poverty. (Contains 1 table, 5 figures and 6 online resources.)

Cost functions are estimated, using random effects and stochastic frontier methods, for English higher education institutions. The article advances on existing literature by employing finer disaggregation by subject, institution type and location, and by introducing consideration of quality effects. Estimates are provided of average incremental…

This article reviews current methods for evaluating models in the cognitive sciences, including theoretically based approaches, such as Bayes factors and minimum description length measures; simulation approaches, including model mimicry evaluations; and practical approaches, such as validation and generalization measures. This article argues…

This article describes how sixth-grade students developed concrete models to solve division of fractions story problems. Students developed separate two-step procedures to solve measurement and partitive problems, drawing on invented procedures for division of whole numbers. Errors also tended to be specific to the type of division problem…

U.S. state educational testing programs administer tests to track student progress and hold schools accountable for educational outcomes. Methods from item response theory, especially Rasch models, are usually used to equate different forms of a test. The most popular method for estimating Rasch models yields inconsistent estimates and relies on…

This paper describes how decisions were made on procedures for counting the homeless population for the 1990 census. These topics are covered: (1) reasons the Census Bureau did not specifically label anyone as "homeless" while still including homeless persons in the census; (2) how the lists of sites where homeless persons might be found were…

Discusses high school students' problems with computation. Presents results from the Third International Mathematics and Science Study (TIMSS), the National Assessment of Educational Progress (NAEP), and research articles to prove that students have difficulty with basic computation. (ASK)

Discusses intelligent tutoring systems and the application of Bayesian networks to student modeling. Considers reasons for not using Bayesian networks, including the computational complexity of the algorithms and the difficulty of knowledge acquisition, and proposes an approach to simplify knowledge acquisition that applies causal independence to…

Medication orders were classified into 17 groups according to the nature of the calculation required and the level of complexity. Except for pediatrics, the frequency with which nurses have to perform other than a simple calculation is low, although the potential for more complex calculations exists. (SK)